如何禁用/启用对话框负正按钮?

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我有一个edittext字段,如果文本字段为空,我想禁用positiveButton。我可以得到一个charListener的文本字段,但我不知道我将如何设置positivebutton?正面和负面按钮的参考是什么?

 case DIALOG_TEXT_ENTRY:
    // This example shows how to add a custom layout to an AlertDialog
    LayoutInflater factory = LayoutInflater.from(this);
    final View textEntryView = factory.inflate(R.layout.alert_dialog_text_entry, null);
    return new AlertDialog.Builder(AlertDialogSamples.this)
        .setIconAttribute(android.R.attr.alertDialogIcon)
        .setTitle(R.string.alert_dialog_text_entry)
        .setView(textEntryView)
        .setPositiveButton(R.string.alert_dialog_ok, new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int whichButton) {
                /* User clicked OK so do some stuff */
            }
        })
        .setNegativeButton(R.string.alert_dialog_cancel, new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int whichButton) {
                /* User clicked cancel so do some stuff */
            }
        })
        .create();
}
提问于
用户回答回答于

编辑完整的解决方案...

AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
builder.setIcon(android.R.drawable.ic_dialog_info);
builder.setTitle("Alert dialog title");
builder.setMessage("This is the example code snippet to disable button if edittext attached to dialog is empty.");
builder.setPositiveButton("PositiveButton",
        new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface arg0, int arg1) {
                // DO TASK
            }
        });
builder.setNegativeButton("NegativeButton",
        new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface arg0, int arg1) {
                // DO TASK
            }
        });
// Set `EditText` to `dialog`. You can add `EditText` from `xml` too.
final EditText input = new EditText(MainActivity.this);
LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(
        LinearLayout.LayoutParams.MATCH_PARENT,
        LinearLayout.LayoutParams.MATCH_PARENT);
input.setLayoutParams(lp);
builder.setView(input);
final AlertDialog dialog = builder.create();
dialog.show();
// Initially disable the button
((AlertDialog) dialog).getButton(AlertDialog.BUTTON_POSITIVE)
        .setEnabled(false);
// OR you can use here setOnShowListener to disable button at first
// time.

// Now set the textchange listener for edittext
input.addTextChangedListener(new TextWatcher() {
    @Override
    public void onTextChanged(CharSequence s, int start, int before,
            int count) {
    }

    @Override
    public void beforeTextChanged(CharSequence s, int start, int count,
            int after) {
    }

    @Override
    public void afterTextChanged(Editable s) {
        // Check if edittext is empty
        if (TextUtils.isEmpty(s)) {
            // Disable ok button
            ((AlertDialog) dialog).getButton(
                    AlertDialog.BUTTON_POSITIVE).setEnabled(false);
        } else {
            // Something into edit text. Enable the button.
            ((AlertDialog) dialog).getButton(
                    AlertDialog.BUTTON_POSITIVE).setEnabled(true);
        }

    }
});
 

这里是一个示例代码,试试这个

AlertDialog.Builder builder = new AlertDialog.Builder(AddSchedule.this);
builder.setIcon(android.R.drawable.ic_dialog_info);
builder.setTitle("Alert dialog title");
builder.setMessage("Dialog message");
builder.setPositiveButton("Button1", new DialogInterface.OnClickListener() {
    public void onClick(DialogInterface arg0, int arg1) {
        //DO TASK
    }
});
builder.setNegativeButton("Button2", new DialogInterface.OnClickListener() {
    public void onClick(DialogInterface arg0, int arg1) {
        //DO TASK
    }
});

AlertDialog dialog = builder.create();
dialog.show();

//After calling show method, you need to check your condition and 
//enable/ disable buttons of dialog 
if(your_condition_true)
    dialog.getButton(AlertDialog.BUTTON1).setEnabled(false); //BUTTON1 is positive button

对于负面按钮

dialog.getButton(AlertDialog.BUTTON2).setEnabled(false); //BUTTON2 is negative button

对于按钮ID参考 alert_dialog.xml

用户回答回答于

我使用自定义布局来完成此任务,其中包含EditText和该视图中的TextWatcher。

final LinearLayout layout = (LinearLayout) inflator.inflate(R.layout.text_dialog, null);
final EditText text = (EditText) layout.findViewById(R.id.text_edit);
final AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setView(layout);
// Now add the buttons...
builder.setPositiveButton(R.string.ok, new AlertDialog.OnClickListener() {
    // Left out for brevity...
}
builder.setNegativeButton(R.string.cancel, new AlertDialog.OnClickListener() {
    // Left out for brevity...
}
// Now add a TextWatcher that will handle enable/disable of save button
text.addTextChangedListener(new TextWatcher() {
    private void handleText() {
        // Grab the button
        final Button okButton = d.getButton(AlertDialog.BUTTON_POSITIVE);
        if(text.getText().length() == 0) {
            okButton.setEnabled(false);
        } else {
            okButton.setEnabled(true);
        }
    }
    @Override
    public void afterTextChanged(Editable arg0) {
        handleText();
    }
    @Override
    public void beforeTextChanged(CharSequence s, int start, int count, int after) {
        // Nothing to do
    }
    @Override
    public void onTextChanged(CharSequence s, int start, int before, int count) {
       // Nothing to do
    }
});
// Create the dialog
AlertDialog d = builder.create();
// show the dialog
d.show();
// and disable the button to start with
d.getButton(AlertDialog.BUTTON_POSITIVE).setEnabled(false);

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